Towards Visual Feedback Loops for Robot-Controlled Additive Manufacturing

Robotic additive manufacturing methods have enabled the design and fabrication of novel forms and material systems that represent an important step forward for architectural fabrication. However, a common problem in additive manufacturing is to predict and incorporate the dynamic behavior of the material that is the result of the complex confluence of forces and material properties that occur during fabrication. While there have been some approaches towards verification systems, to date most robotic additive manufacturing processes lack verification to ensure deposition accuracy. Inaccuracies, or in some instances critical errors, can occur due to robot dynamics, material self-deflection, material coiling, or timing shifts in the case of multi-material prints. This paper addresses that gap by presenting an approach that uses vision-based sensing systems to assist robotic additive manufacturing processes. Using online image analysis techniques, occupancy maps can be created and updated during the fabrication process to document the actual position of the previously deposited material. This development is an intermediary step towards closed-loop robotic control systems that combine workspace sensing capabilities with decision-making algorithms to adjust toolpaths to correct for errors or inaccuracies if necessary. The occupancy grid map provides a complete representation of the print that can be analyzed to determine various key aspects, such as, print quality, extrusion diameter, adhesion between printed parts, and intersections within the meshes. This valuable quantitative information regarding system robustness can be used to influence the system’s future actions. This approach will help ensure consistent print quality and sound tectonics in robotic additive manufacturing processes, improving on current techniques and extending the possibilities of robotic fabrication in architecture

Children's views and strategies for making friends in linguistically diverse English medium instruction settings

Despite one in four children in Australia entering preschool using English as an additional language or dialect (EAL/D) (Australian Bureau of Statistics (ABS), 2017), Australian classrooms are predominantly monolingual English-speaking. This mismatch in languages may affect how participation and relationships are established. This chapter explores children’s strategies for making friends in settings characterised by linguistic diversity but where the medium of instruction is English. Child friendly interviews (video recorded) with 72 preschool-aged children, 3-4 years, were conducted in at a preschool in inner-city centre. Children were asked to talk and draw a picture about making friends when there are language differences. Children’s responses not only revealed their competencies in using non-verbal strategies to communicate with each other but also reflected inclusive attitudes. The importance of using a variety of languages as media of instruction, such as including songs and words representative of the minority languages of the classroom, and having conversations about language difference are highlighted